Pros And Cons Of Wastegate Feed Positions

[bradsm87]

stretching them the other way to the direction they're designed to go, wearing them out quicker. The dodgiest bit is at 60-90% throttle tho. The wastegate thinks the turbo's only producing 10psi so closes right up, meanwhile the turbo could be pushing 25psi before the throttle body. U can hear it as u back off a bit. Dodgy imo.

[rob82]

Using a vacuum reference is a really shit idea - not only are you causing a vacuum leak as you bleed the solenoid onto boost but your also applying negative pressure on the actuator meaning that its more likely to open the wastegate flap so it will make the car slower onto boost. Not only this but if gases are escaping out of the the wastegate port then your putting more thermal loading on wastegeate port - guess where turbos are likely to crack!!

[bradsm87]

Nah under vacuum if anything, would hold the wastegate closed harder. I agree vacuum is bad tho.

[zebra]

how is vacuum gonna hurt them?

This is what i would like to know too.

Like I said before, I had the same setup on my Gtst with no dramas, the whole point of this exersise is to hold the wastegates shut for as long as possible, not constantly bleeding off exhaust gas.

[BK]

ok I'm bumping this.

Boost pressure source for wastegate / boost solenoid - plenum or compressor housing ?

I've always been plenum, but seeing all of the Precision / Borg Warner / Garrett singles now with nipples on the compressor housings is making me think twice, especially since I've moved to a 6466.

Surely plenum is the go as that is what the engine is seeing and what you want to control ? So why have compressor nipples then ?

I am talking RB26 here so I do realise pressure source always has to be before the throttles (like the plenum), unlike a 25 where the plenum is after the single throttle body making the plenum a no go in that situation.

[GTSBoy]

There is no difference between plenum and comp housing on an ITB 26.......well, there is a small difference related to the speed of sound and the propagation rate of the pressure signal. I think Nissan did it in the plenum on the 26 because it was a reasonable place to pick up a signal from both turbos. That's all.